Refrigeration



June 20, 1933. A. LENNING v1,914,861

REFRIGERATION Filed Sept. 15, 1928 I- xwmmw IN NTOR with due regard RATEQN, @F N YGREZ, N.

'QVEL CURFlO- l /ly invention relates to refrigeratino' apparatus and more particularly rerrigerating apparatus wherein a plurality of substances have complementary diffusion in heat exchange with the objective of refrigeration.

I will describe a y invention with reierence to an apparatus or the type shown in l Pat. re. 1,808,?23, granted June 2, 1931 to Munters as this will make the invention readily understandable though it is to he understood, as will become apparent, that the invention is not limited to refrigerating apparati or that type.

A refrigerating apparatus is designed the work which it is to accomplish. That is, a refrigerating apparatus is designed for a given capacity.

The capacity of a standard refrigerating apparatus or the type above referred to can be varied by varying the concentration oi the solution in the same, that is by varying the proportion of amount of refrigerant or cooling agent, such as ammonia, to the amount of absorption liquid, such as water, other factors remaining constant. Assume, tor the purpose of illustration, that a certain apparatus is designed for normal connition but that the apparatus is used in an unusually torrid climate where the load is greater than the apparatus can take care of. If the excess of load is not too great, the apparatus can be made to have a greater capacityand take care of the load by Weakening the solution. While this is accomplished at a sacrifice of some etliciency, so that a greater energy input is necessary, it is some times advisable and ultimately economical despite the lower efiiciency to use apparati with weaker solution where the load is as above indicated.

Even an apparatus operating generally under normal conditions some times has to take care of unusual conditions Where a weak solution is desirable. It is obviously impractical to alter the fluid content of apparati.

The present invention has for its object to vary the capacity of a refrigerating apparatus of the type referred to and of simine proamounts oi dinerent iiuids so v I: 1 ill the type or ao mates aoove to the lim't of capacity is reached when liquid cooling agent passes out of the evanolator without e oratin By accuiniilating tins unevaporated cooling automatically within the system, a able to accomplish the desired change in manner so that the apparatus is ahle automatically chan e itself from an apparatus or" one type of charge to an apparat s of a diflerent type charge. A l

The invention will he explained with reference to the accompanying drawing on which p 1 shows apparatus of the type above referred to embodying the present iiivention, and i Fig. 2 shows a modified form or" he apparatus illustrated in Fig. l. l

The system of apparatus shown in Fig. 1 comprises a generator 10 which is divided by a partition 13 into two parts, a main generator 11 and an auxiliary generator 12. A flue it extends centrally through both auxiliary generator 12 and the main generator 11. A suitable source of heat, as for example the gas burner 15, is located below, and may extend upwardly within, flue 14. A thermosyphon conduit '16 establishes communication between auxiliary generator 12 and main generator 11. The lower end of conduit 16 extends for some distance within auxiliary generator 12. The portion of conduit 16 within auxiliary generator '12 is provided with one or more capillary ports 17.

A conduit 18 communicates with the upper part of main generator 11 and extends, inclined to the horizontal, upwardly to rec tifier 20. Rectifier 20 comprises a Ll-shaped member 21 around one branch of which is a member 22 to which conduit 18 is cono 3. v i

lllld nected. Connected to the upper part of member 22 is a condenser tube 23 which passes in heat exchange relation with a cooling water conduit 24 and is connected to a branch of U-shaped member 21. The branch of the U-shaped member 21 which is within jacket member 22 is open at the top so that it communicates with condenser tube 23 and is surrounded by bafiles 25.

A conduit 26 is connected to the lower part of the rectifier, extends downwardly within conduit 27, horizontally through heat exchanger 28, upwardly through conduit 29 and terminates in a bend 30 which extends into an evaporator 31 situated within the space to be cooled. A conduit 32 connects the lower part of the evaporator 31 with heat exchanger 28. The heat exchanger comprises a head 33 and a head 34 forming end chambers 35 and 36. These end chambers are connected by tubes 37. A space 38 is formed between heads 33 and 34 and outside tubes 26 and 37. To this space 38 conduit 32 is connected. A conduit 39 connects the lower part of space 38 with the lower part of an absorber 40. Conduit 27 connects the upper part of absorber 40 with chamber 35. The evaporator and absorber contain apertured disks 41 for obtaining gas and liquid contact.

A conduit 42 connects the lower part of absorber 40 with the upper part of auxiliary generator 12. A conduit 43 connects the lower part of main generator 11 with the.

upper part of absorber 40. These conduits are arranged in heat exchange relation as indicated at 44.

So far I have described, in a general way, the above referred to type of system. I shall now explain its operation in general and then point out the nature of the present improvement. The operation is as follows:

Heat applied to the main generator 11 drives ammonia out of solution. Ammonia vapor with some entrained vapor of absorption liquid passes through conduit 18 to the rectifier where the absorption-liquid vapor is condensed and caused to return toward the generator through conduit 18. The absorption liquid used is preferably water. The cooling to effect the separation of absorptlon liquid is obtained due to the presence of liquid ammonia in the U-shaped member 21 which has been condensed in condenser tube 23. Ammonia vapor passes into conduit 23 from both member 22 outside the U-shaped member and from above the surface of liquid in that part of the U-shaped member 21 which is within member 22.

Liquefied ammonia passes through conduit 26 and into evaporator 31 where it flows over the disks 41. Hydrogen is admitted to the evaporator through conduit 29. The ammonia diffuses into the hydrogen and evaporates thus taking up heat from the surroundings and producing refrigeration. A mixture of hydrogen and ammonia gas is formed which passes downwardly through conduit 32 and through space 38 and conduit 39 into the lower part of absorber 40. In the absorber 4O weak absorptionliquid separates ammonia from the hydrogen and the liberated hydrogen passes through conduit 27 space 35, tubes 37 space 36 and conduit 29 into the evaporator. Circulation of the hydrogen is produced between the evaporator and absorber due to the difference in specific weight of a mixture of ammonia gas and hydrogen on the one hand and hydrogen alone on the other hand.

Strong absorption liquid flows through conduit 42 and is lifted, due to heat, through thermo-syphon tube 16 to main generator 11. The weak absorption liquid from which ammonia has been expelled passes through conduit 43 into the upper part of absorber 40 and flows over disks 41. Circulation between the absorber and generator is produced by the lifting effect of auxiliary generator 12 and thermo-syphon tube 16.

Dealing now with the present improvement to the above described system, I have provided a bowl-shaped member 50 in the lower part of the absorber 40. The upper edge 0 this member is arranged above the lower part of the connection of conduit 39 to absorber 40 so that liquid flowing from conduit 39 into absorber 40 passes into a space 51 which is between member 50 and the outer shell of the absorber. Conduit 42 is connected to the inner space 52 of member 50. A small connection 53 is provided at the bottom of member 50 so that absorption liquid within space 52 has restricted communication with absorption liquid in space 51.

Space 51 contains a pool of liquid which is isolated fromthe cycle of flow of the fluids within the system. This pool of liquid may be termed relatively stagnant. Assume now that some of the cooling agent, ammonia, passes through the evaporator without evaporating. In this condition the limit of capacity of the apparatus has been reached. This unevaporated liquid cooling agent passes along the lower part of heat exchanger 28 and through conduit 39 into space 51. Here it increases the concentration of the absorption liquid. The small size of opening 53 prevents to a great extent the difiusion of ammonia through absorption liquid into the space 52 and so an appreciable amount of ammonia is accumulated in space 51. By thus accumulating the cooling agent out of the path of flow the concentration of the absorption liquid is de creased. Consequently, the capacity of the apparatus is increased automatically by this accumulation, as above stated.

By accumulating ammonia, the solution entering the top of the absorber through conduit 43 has become weaker in ammonla. Inasmuch as the partial pressure of ammonia in the weak gas leaving the upper part of the absorber through conduit 27 has a relation to the strength of the ammonia solution entering the absorber, the weak gas has also become weaker in ammonia. Consequently this gas, when passing through the evaporator, can evaporate a larger amount of ammonia than before, even at a lower temperature, with the result that the capacity of the apparatus will be increased.

When the demand for cooling effect is lessened, and the heat supply to the generator has been reduced accordingly, a lesser amount of liquid ammonia will pass out of the evaporator. The liquid ammonia accumulated in space 51 will then diffuse through the opening 53, into the cycle of flow faster than liquid ammonia entering the top of space 51. Thus the apparatus automatically brings itself back to the initial condition.

A member 54 may be placed above member 50 to insure the flow of cycle fluid into space 52.

In Fig. 2 is shown a modified arrangement wherein a partition 55 is placed across the bottom of the absorber having a lower opening 53 and having its upper end extending above the lower part of conduit 39. This partition forms two spaces 51 and 52 which are the same in function as the spaces 51 and 52 of Fig. 1.

\Vhile I have described my invention in connection with a particular form of apparatus, it will be understood that the principle of accumulating fluid out of cycle flow in order to change the fluid proportion within the apparatus and automaticallychange the capacity of the apparatus may be applied to other types of apparatus,

Having thus described my invention what I claim is:

1. Refrigerating apparatus comprlsing an evaporator, an absorber, means to conduct a cooling agent into the evaporator and thence to the absorber, means to circulate an auxiliary agent between the absorber and evaporator and means dependent on load to automatically accumulate liquid cooling agent passing from the evaporator toward the absorber and to supply the accumulated refrigerant to the absorber at a rate different from the rate of accumulation.

2. Refrigerating apparatus comprising an evaporator, an absorber, means to conduct a cooling agent into the evaporator and thence to the absorber, means to circulate an auxiliary agent between the absorber and evaporator and means in the absorber to accumulate liquid cooling agent passing from the evaporator to the absorber.

3. Refrigerating apparatus comprising an cycle for circulation of an auxiliary agent between the absorber and evaporator and means for accumulating cooling agent having a fixed restricted liquid communication with the absorption liquid cycle.

5. Refrigerating apparatus comprising a generator, a condenser, an absorber, an evaporator, conduits forming a cycle for circulation of absorption liquid between the generator and absorber, a cycle for circulation of cooling agent through the generator, condenser, evaporator and absorber and a cycle for circulation of an auxiliary agent between the absorber and evaporator and means for forming a receptacle adapted to receive absorption liquid and having continuous liquid communication with the absorption liquid cycle for accumulating cooling agent.

6. Refrigerating apparatus comprising a generator, a condenser, an absorber, an evaporator, conduits forming a cycle for circulation of absorption liquid between the generator and absorber, a cycle for circulation of cooling agent through the generator,. condenser, evaporator and absorber and a cycle for circulation of an auxiliary agent between the absorber and evaporator and means for forming a receptacle adapt ed to receive absorption liquid and having continuous liquid communication with the absorption liquid cycle for accumulating liquid cooling agent passing from the evaporator toward the absorber.

7. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing, the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and automatically varying the relative proportions of circulating fluids by accumulating cooling agent.

8. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and varying the relative proportions of circulating fluids by automatically withdrawing cooling agent from the active circulatory portion of the system in varying amounts dependent on variations in load and returning the same thereto at a rate different from the rate of withdrawal.

9. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and automatically varymg the relative proportion of cooling agent to auxiliary agent circulating in the active circulatory portion of the system by accumulating cooling agent.

10. The method of producing refrigeration through the agency of an absorption system which comprises expelling a coolin agent from solution in an absorption liqui converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and, the place of expelling, and varying the relative proportion of cooling agent to auxiliary agent circulating in the active circulatory portion ozf the system by at times accumulating some of the cooling agent in a relatively stagnant pool having continuous restricted communication with the active circulatory portion of the system.

11. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the )lace of absorption and the place of expel ing, and varying the relative proportion of cooling agent to auxiliary agent circulating in the active circulatory portion of the system by at times accumulating some of the cooling agent in a relatively stagnant pool having continuous restricted communication with the absorption liquid circuit.

12. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and automatically changing the concentration of the absorption liquid in accordance with variations in load by accumulating cooling agent.

13. The method of producing refrigeration through the agency of an absorption system which comprisesexpelling a cooling agent from solution'in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and automatically decreasing the concentration of the absorption liquid when there is an excess of unevaporated cooling agent in the place of evaporation.

14. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid, converting the cooling agent to liquid phase, evaporating the cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and automatically decreasing the concentration of the absorption liquid when there is an excess of unevaporated cooling agent in the place of evaporation by accumulating cooling agent.

15. Refrigerating apparatus comprising a generator, a condenser, an evaporator, an absorber, means for circulating a cooling agent through the aforementioned parts, an auxiliary agent through the absorber and evaporator, and absorption liquid through the generator and absorber, and means for automatically accumulating cooling agent to change the concentration of the absorption liquid in accordance with variations in load.

16. Refrigerating apparatus comprising a generator, a condenser, an evaporator, an absorber, means for circulating a cooling agent through the aforementioned parts, an auxiliary agent through the absorber and evaporator, and absortion liquid through the generator and absorber, and means to automatically decrease the concentration of the absorption liquid when there is an excess of unevaporated liquid refrigerant in the evaporator.

17. Refrigerating apparatus comprising a generator, a condenser, an evaporator, an absorber, means for circulating a cooling agent through the aforementioned parts, an auxiliary agent through the absorber and evaporator, and absorption liquid through the generator and absorber, and means adapted to receive liquid from the evaporator and to supply liquid to the absorber and operating automatically to decrease the concentration of the absorption liquid when excess liquid cooling agent flows out of the evaporator.

18. A continuous absorption apparatus having a generator-absorber system including a generator and an absorber and circulation means therebetween, an evaporator, and gas circulating conduits between the absorber and the evaporator for circulating a mixture of inert gas and gaseous operating medium between the evaporator and the absorber, in combination with means for altering the average concentration of circulating absorption liquid comprising a liquid storage receptacle having a non-circulating connection to the absorption liquid circuit.

19. The method of producing refrigeration through the agency of an absorption system which comprises expelling a cooling agent from solution in an absorption liquid,

converting thecooling agent to liquid phase,

evaporating the-cooling agent in the presence of an auxiliary agent, absorbing the cooling agent in the absorption liquid, circulating the auxiliary agent between the place of evaporation and the place of absorption, circulating the absorption liquid between the place of absorption and the place of expelling, and varying the relative proportion of fluids circulating in the active circulatory portion of the system by providing a relatively stagnant quantity of absorption liquid external to and in communication with the active circulatory portion of the system and varying fluid transfer between said relatively stagnant quantity and the active circulatory portion of the system.

20. In the method of refrigeration comprising continuous circulation of heat conducting fluid and evaporation thereof into an auxiliary agent, absorption thereof into liquid solution, expulsion thereof from said solution, and condensation thereof to liquid, the step which consists in changing the average concentration of said solution by trapping a portion of said heat conducting fluid out of circulation.

21. In the method of refrigeration comprising continuous circulation of heat con ducting fluid and evaporation thereof into an auxiliary agent, absorption thereof into liquid solution, expulsion thereof from said solution, and condensation thereof to liquid, the step which consists in controlling the average concentration of said solution by trapping varying amounts of said heat conducting fiuid out of circulation.

in testimony whereof I have affixed my signature.

ALVAR LENNING. 

